@allmaps/warpedmaplayer

Base class for Allmaps plugins. This class contains the main logic for the WarpedMapLayer class exported by the Leaflet, OpenLayers and MapLibre plugins for Allmaps, which allow displaying georeferenced IIIF images on a webmap. These plugins work by loading Georeference Annotations and use WebGL to transform images from a IIIF image server to overlay them on their correct geographical position.

How it works

This plugin creates a new class WarpedMapLayer which extends or is implemented by the Layer classes of the webmap libraries Leaflet, OpenLayers and MapLibre. Where it extends (MapLibre), the methods defined in this package are inherited automatically. Where it is implemented (Leaflet and OpenLayers) any changes to these methods should be copy-pasted to the implementing classes (see comments in the code).

To understand what happens under the hood for each georeferenced map, see the @allmaps/render package.

Installation

This package works in browsers and in Node.js as an ESM or an UMD module.

Install with pnpm:

pnpm install @allmaps/warpedmaplayer

You can optionally build this package locally by running:

pnpm run build

Usage

This package contains the main logic for the WarpedMapLayer class exported by the Allmaps plugins for Leaflet, OpenLayers and MapLibre. It should not be used directly. See the readme of the plugins for more usage information.

Use this readme to understand the API of the WarpedMapLayer methods shared between the plugins, including event types emitted by a WarpedMapLayer instance and a list of available options.

Events

The following events are emitted by the native map object to inform you of the state of the WarpedMapLayer.

| Type | Description | |---------------------------------|--------------------------------------------------------------------------------------------------------------------------------------| | imageinfosadded | Image infos have been directly added into the warped map list | | georeferenceannotationadded | A georeference annotation has been added to the warped map list | | georeferenceannotationremoved | A georeference annotation has been removed from the warped map list | | warpedmapadded | A warped map has been added to the warped map list | | warpedmapremoved | A warped map has been removed from the warped map list | | warpedmapentered | A warped map has entered the viewport | | warpedmapleft | A warped map has left the viewport | | imageloaded | An image was loaded for a map from cache or by fetching image info | | maptilesloadedfromsprites | Tiles have been loaded to the tile cache from a fetched sprites image map | | maptileloaded | A tile has been loaded to the tile cache for a map | | maptiledeleted | A tile has been deleted from the tile cache for a map | | firstmaptileloaded | The cache loaded a first tile of a map | | allrequestedtilesloaded | All tiles requested for the current viewport have been loaded | | cleared | The warped map list has been cleared | | preparechange | An upcoming options change has been prepared for a specific map (by mixing previous and new properties if the animation was ongoing) | | immediatechange | An options change has been processed immediately | | animatedchange | An options change has been processed with an animation |

Event data follows the Partial<WarpedMapEventData> type:

export type WarpedMapEventData = {
  mapIds: string[]
  tileUrl: string
  optionKeys: string[]
  spritesInfo: SpritesInfo
}

Options

Options can be set on a WarpedMapLayer both as layer options, which apply to all maps, or as individual map options. For each map, the final options that are applied to it result from merging the default options, options specified in the georeference annotation (like resourceMask, transformationType, internalProjection and gcps), layer options and map options. When merging options, undefined options are neglected, so setting a layer or map option to undefined effectively resets it.

The following options are available:

| Key | Description | Default | |------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------| | applyMask | Apply the resource mask (if false, the full mask is used) | true | | colorize | Colorize the map | false | | colorizeColor | Color to colorize the map | "#ff56ba" | | debugTiles | Debug: show the tile boundaries | false | | debugTriangles | Debug: show the triangulation triangles | false | | debugTriangulation | Debug: show the triangulation triangle points | false | | distortionColor00 | First color in the 'log2sigma' distortion | "#fe5e60" | | distortionColor01 | Second color in the 'log2sigma' distortion | "#3b44ad" | | distortionColor1 | Color in the 'twoOmega' distortion | "#64c18f" | | distortionColor2 | Color in the 'airyKavr' distortion | "#ffc742" | | distortionColor3 | Color in the 'signDetJ' distortion | "#fe5e60" | | distortionMeasures | Distortion measures to be computed | ['log2sigma', 'twoOmega'] | | gcps | Ground control points | [] (overwritten by the GCPs in the georeference annotation) | | internalProjection | Internal projection (see @allmaps/project) | WebMercatorProjection (possibly overwritten by the internal projection in the georeference annotation) | | opacity | Opacity | 1 | | projection | Projection (see @allmaps/project) | WebMercatorProjection | | removeColor | Remove color | false | | removeColorColor | Color to remove | "#222222" | | removeColorHardness | Hardness when removing color | 0.7 | | removeColorThreshold | Threshold when removing color | 0 | | renderAppliableMask | Render the appliable mask, which is the resource mask as specified in the georeferenced annotation (or options), even when the mask is not applied (see the applyMask option) and the full mask is used | false | | renderAppliableMaskColor | Color when rendering the appliable mask | "#ff56ba" | | renderAppliableMaskSize | Size in viewport pixels when rendering the appliable mask | 8 | | renderFullMask | Render the full mask | false | | renderFullMaskColor | Color when rendering the full mask | "#64c18f" | | renderFullMaskSize | Size in viewport pixels when rendering the full mask | 8 | | renderGcps | Render the GCPs | false | | renderGcpsColor | Color when rendering the GCPs | "#63d8e6" | | renderGcpsSize | Size in viewport pixels when rendering the GCPs | 16 | | renderGrid | Render the grid | false | | renderGridColor | Color when rendering the grid | "#222222" | | renderMask | Render the mask | false | | renderMaskColor | Color when rendering the mask | "#ff56ba" | | renderMaskSize | Size in viewport pixels when rendering the mask | 8 | | renderTransformedGcps | Render the transformed GCPs | false | | renderTransformedGcpsColor | Color when rendering the transformed GCPs | "#ff56ba" | | renderTransformedGcpsSize | Size in viewport pixels when rendering the transformed GCPs | 16 | | renderVectors | Render the vectors connecting each GCP with its respective transformed GCP | false | | renderVectorsColor | Color when rendering the vectors | "#222222" | | renderVectorsSize | Size in viewport pixels when rendering the vectors | 6 | | resourceMask | Resource mask | [] (overwritten by the resource mask in the georeference annotation) | | saturation | Saturation | 1 | | transformationType | Transformation type | "polynomial" (possibly overwritten by the transformation type in the georeference annotation) | | visible | Visible | true |

What is a map?

Leaflet, OpenLayer and MapLibre each have their concept of a 'map' as the central class their API (see Leaflet Map, OpenLayers Map and MapLibre Map). It generally refers to a <div> an a page where tiles or WebGL logic is used to render a projection of the world.

In Allmaps the concept 'map' is rather related to a Georeference Annotation. There are different classes named 'map', one for each phase a map takes through the Allmaps rendering pipeline:

• When a Georeference Annotation is parsed, an instance of the GeoreferencedMap class is created from it.
• When this map is loaded into an application for rendering, an instance of the WarpedMap class is created from it.
• Inside the WebGL2 Renderer, the WebGL2WarpedMap class is used to render the map.

All these map phases originating from the same Georeference Annotation have the same unique mapId property. This string value is used though-out Allmaps (and in the API below) to identify a map. It is returned after adding a georeference annotation to a warpedMapLayer, so you can use it later to call functions on a specific map.

Note that since a WarpedMapLayer can load multiple Georeference Annotations, we could have multiple Allmaps 'maps' on e.g. one Leaflet 'map'.

License

MIT

API

new BaseWarpedMapLayer(defaultSpecificWarpedMapLayerOptions, options)

Creates a WarpedMapLayer instance

Parameters

• defaultSpecificWarpedMapLayerOptions (SpecificWarpedMapLayerOptions)
• options? ( | Partial<SpecificWarpedMapLayerOptions & Partial<WebGL2RenderOptions>> | undefined)
  • options

Returns

BaseWarpedMapLayer<SpecificWarpedMapLayerOptions>.

BaseWarpedMapLayer#addEventListeners()

Parameters

There are no parameters.

Returns

void.

BaseWarpedMapLayer#addGeoreferenceAnnotation(annotation, mapOptions)

Adds a Georeference Annotation

Parameters

• annotation (unknown)
  • Georeference Annotation
• mapOptions? (Partial<WebGL2WarpedMapOptions> | undefined)
  • Map options

Returns

Map IDs of the maps that were added, or an error per map (Promise<Array<string | Error>>).

BaseWarpedMapLayer#addGeoreferenceAnnotationByUrl(annotationUrl, mapOptions)

Adds a Georeference Annotation by URL

Parameters

• annotationUrl (string)
  • URL of a Georeference Annotation
• mapOptions? (Partial<WebGL2WarpedMapOptions> | undefined)
  • Map options

Returns

Map IDs of the maps that were added, or an error per map (Promise<Array<string | Error>>).

BaseWarpedMapLayer#addGeoreferencedMap(georeferencedMap, mapOptions)

Adds a Georeferenced Map

Parameters

• georeferencedMap (unknown)
  • Georeferenced Map
• mapOptions? (Partial<WebGL2WarpedMapOptions> | undefined)
  • Map options

Returns

Map ID of the map that was added, or an error (Promise<string | Error>).

BaseWarpedMapLayer#addImageInfos(imageInfos)

Adds image information to the WarpedMapList's image information cache

Parameters

• imageInfos (Array<unknown>)
  • Image informations

Returns

Image IDs of the image informations that were added (Array<string>).

BaseWarpedMapLayer#addSprites(sprites, imageUrl, imageSize)

Adds sprites to the Renderer's sprite tile cache

This adds tiles from sprites to warped maps in WarpedMapList. Load maps before running this function. This uses the image info of related maps. When using addImageInfos(), call it before calling this function.

Parameters

• sprites (Array<Sprite>)
  • Sprites
• imageUrl (string)
  • Image url
• imageSize ([number, number])
  • Image size

Returns

Promise<void>.

BaseWarpedMapLayer#bringMapsForward(mapIds)

Bring maps forward

Parameters

• mapIds (Iterable<string>)
  • IDs of the maps

Returns

void.

BaseWarpedMapLayer#bringMapsToFront(mapIds)

Bring maps to front

Parameters

• mapIds (Iterable<string>)
  • IDs of the maps

Returns

void.

BaseWarpedMapLayer#canvas?

Type

HTMLCanvasElement

BaseWarpedMapLayer#clear()

Removes all warped maps from the layer

Parameters

There are no parameters.

Returns

void.

BaseWarpedMapLayer#container?

Type

HTMLDivElement

BaseWarpedMapLayer#contextLost(event)

Parameters

• event (Event)

Returns

void.

BaseWarpedMapLayer#contextRestored(event)

Parameters

• event (Event)

Returns

void.

BaseWarpedMapLayer#defaultSpecificWarpedMapLayerOptions

Type

SpecificWarpedMapLayerOptions

BaseWarpedMapLayer#getDefaultOptions()

Get the default options the layer

Parameters

There are no parameters.

Returns

SpecificWarpedMapLayerOptions & object & SpecificWarpedMapListOptions & Partial<WebGL2WarpedMapOptions> & SpecificWebGL2WarpedMapOptions & SpecificTriangulatedWarpedMapOptions & WarpedMapOptions.

BaseWarpedMapLayer#getLayerOptions()

Get the layer options

Parameters

There are no parameters.

Returns

{ [P in keyof (SpecificWarpedMapLayerOptions & Partial<WebGL2RenderOptions>)]?: (SpecificWarpedMapLayerOptions & Partial<...>)[P] | undefined; }.

BaseWarpedMapLayer#getMapDefaultOptions(mapId)

Get the default options of a map

These come from the default option settings for WebGL2WarpedMaps and the map's georeferenced map proporties

Parameters

• mapId (string)
  • Map ID for which the options apply

Returns

WebGL2WarpedMapOptions | undefined.

BaseWarpedMapLayer#getMapIds()

Get mapIds for selected maps

Note: more selection options are available on this function of WarpedMapList

Parameters

There are no parameters.

Returns

Array<string>.

BaseWarpedMapLayer#getMapMapOptions(mapId)

Get the map-specific options of a map

Parameters

• mapId (string)
  • Map ID for which the options apply

Returns

Partial<WebGL2WarpedMapOptions> | undefined.

BaseWarpedMapLayer#getMapOptions(mapId)

Get the options of a map

These options are the result of merging the default, georeferenced map, layer and map-specific options of that map.

Parameters

• mapId (string)
  • Map ID for which the options apply

Returns

WebGL2WarpedMapOptions | undefined.

BaseWarpedMapLayer#getMapZIndex(mapId)

Get the z-index of a map

Parameters

• mapId (string)
  • Map ID for which to get the z-index

Returns

The z-index of a map (number | undefined).

BaseWarpedMapLayer#getMapsBbox(mapIds, projectionOptions)

Get the bounding box of the maps

By default the result is returned in the list's projection, which is EPSG:3857 by default Use {definition: 'EPSG:4326'} to request the result in lon-lat EPSG:4326

Note: more selection options are available on this function of WarpedMapList

Parameters

• mapIds (Array<string>)
  • Map IDs
• projectionOptions? (ProjectionOptions | undefined)

Returns

The bbox of all selected maps, in the chosen projection, or undefined if there were no maps matching the selection (Bbox | undefined).

BaseWarpedMapLayer#getMapsCenter(mapIds, projectionOptions)

Get the center of the bounding box of the maps

By default the result is returned in the list's projection, which is EPSG:3857 by default Use {definition: 'EPSG:4326'} to request the result in lon-lat EPSG:4326

Note: more selection options are available on this function of WarpedMapList

Parameters

• mapIds (Array<string>)
  • Map IDs
• projectionOptions? (ProjectionOptions | undefined)

Returns

The center of the bbox of all selected maps, in the chosen projection, or undefined if there were no maps matching the selection (Point | undefined).

BaseWarpedMapLayer#getMapsConvexHull(mapIds, projectionOptions)

Get the convex hull of the maps

By default the result is returned in the list's projection, which is EPSG:3857 by default Use {definition: 'EPSG:4326'} to request the result in lon-lat EPSG:4326

Note: more selection options are available on this function of WarpedMapList

Parameters

• mapIds (Array<string>)
  • Map IDs
• projectionOptions? (ProjectionOptions | undefined)

Returns

The convex hull of all selected maps, in the chosen projection, or undefined if there were no maps matching the selection (Ring | undefined).

BaseWarpedMapLayer#getOpacity()

Get the layer opacity

Returns a number between 0 and 1 (the default)

Parameters

There are no parameters.

Returns

number.

BaseWarpedMapLayer#getWarpedMap(mapId)

Get the WarpedMap instance for a map

Parameters

• mapId (string)
  • Map ID of the requested WarpedMap instance

Returns

WebGL2WarpedMap | undefined.

BaseWarpedMapLayer#getWarpedMapList()

Get the WarpedMapList object that contains a list of the warped maps of all loaded maps

Parameters

There are no parameters.

Returns

WarpedMapList<WebGL2WarpedMap>.

BaseWarpedMapLayer#getWarpedMaps(mapIds)

Get the WarpedMap instances for selected maps

Note: more selection options are available on this function of WarpedMapList

Parameters

• mapIds? (Array<string> | undefined)
  • Map IDs

Returns

Iterable<WebGL2WarpedMap>.

BaseWarpedMapLayer#gl

Type

WebGL2RenderingContext | null | undefined

BaseWarpedMapLayer#nativePassWarpedMapEvent(event)

Parameters

• event (Event)

Returns

void.

BaseWarpedMapLayer#nativeUpdate()

Parameters

There are no parameters.

Returns

void.

BaseWarpedMapLayer#options

Type

SpecificWarpedMapLayerOptions & Partial<WebGL2RenderOptions>

BaseWarpedMapLayer#removeEventListeners()

Parameters

There are no parameters.

Returns

void.

BaseWarpedMapLayer#removeGeoreferenceAnnotation(annotation)

Removes a Georeference Annotation

Parameters

• annotation (unknown)
  • Georeference Annotation

Returns

Map IDs of the maps that were removed, or an error per map (Promise<Array<string | Error>>).

BaseWarpedMapLayer#removeGeoreferenceAnnotationByUrl(annotationUrl)

Removes a Georeference Annotation by URL

Parameters

• annotationUrl (string)
  • URL of a Georeference Annotation

Returns

Map IDs of the maps that were removed, or an error per map (Promise<Array<string | Error>>).

BaseWarpedMapLayer#removeGeoreferencedMap(georeferencedMap)

Removes a Georeferenced Map

Parameters

• georeferencedMap (unknown)
  • Georeferenced Map

Returns

Map ID of the map that was removed, or an error (Promise<string | Error>).

BaseWarpedMapLayer#removeGeoreferencedMapById(mapId)

Removes a Georeferenced Map by its ID

Parameters

• mapId (string)
  • Map ID of the georeferenced map to remove

Returns

Map ID of the map that was removed, or an error (Promise<string | Error | undefined>).

BaseWarpedMapLayer#renderer?

Type

WebGL2Renderer

BaseWarpedMapLayer#resetLayerOptions(layerOptionKeys, animationOptions)

Reset the layer options

An empty array resets all options, undefined resets no options. Doesn't reset render options or specific warped map layer options

Parameters

• layerOptionKeys? (Array<string> | undefined)
  • Keys of the options to reset
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

BaseWarpedMapLayer#resetMapsOptions(mapIds, mapOptionKeys, layerOptionKeys, animationOptions)

Reset the map-specific options of maps (and the layer options)

An empty array resets all options, undefined resets no options. Doesn't reset render options or specific warped map layer options

Parameters

• mapIds (Array<string>)
  • Map IDs for which to reset the options
• mapOptionKeys? (Array<string> | undefined)
  • Keys of the map-specific options to reset
• layerOptionKeys? (Array<string> | undefined)
  • Keys of the layer options to reset
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

BaseWarpedMapLayer#resetMapsOptionsByMapId(mapOptionkeysByMapId, layerOptionKeys, animationOptions)

Reset the map-specific options of maps by map ID (and the layer options)

An empty array or map resets all options (for all maps), undefined resets no options. Doesn't reset render options or specific warped map layer options

Parameters

• mapOptionkeysByMapId (Map<string, Array<string>>)
  • Keys of map-specific options to reset by map ID
• layerOptionKeys? (Array<string> | undefined)
  • Keys of the layer options to reset
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

BaseWarpedMapLayer#sendMapsBackward(mapIds)

Send maps backward

Parameters

• mapIds (Iterable<string>)
  • IDs of the maps

Returns

void.

BaseWarpedMapLayer#sendMapsToBack(mapIds)

Send maps to back

Parameters

• mapIds (Array<string>)
  • IDs of the maps

Returns

void.

BaseWarpedMapLayer#setLayerOptions(layerOptions, animationOptions)

Set the layer options

Parameters

• layerOptions (Partial<WebGL2RenderOptions> | Partial<SpecificWarpedMapLayerOptions>)
  • Layer options to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

Examples

warpedMapLayer.setLayerOptions({ transformationType: 'thinPlateSpline' })

BaseWarpedMapLayer#setMapGcps(mapId, gcps, animationOptions)

Set the GCPs of a map

This only sets the map-specific gcps option of the map (or more specifically of the warped map used for rendering), overwriting the original GCPs inferred from the Georeference Annotation.

The original GCPs can be reset by resetting the map-specific GCPs option, and stay accessible in the warped map's map property.

Parameters

• mapId (string)
  • Map ID for which to set the options
• gcps (Array<Gcp>)
  • GCPs to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

BaseWarpedMapLayer#setMapOptions(mapId, mapOptions, layerOptions, animationOptions)

Set the map-specific options of a map (and the layer options)

In general setting a map-specific option also sets the corresponding option of the map, since these are the result of merging the default, georeferenced map, layer and map-specific options of that map.

A special case is setting a map-specific option to undefined: then the corresponding option is derived from the default, georeferenced map or layer option. This is equivalent to using the reset function for map-specific option.

Parameters

• mapId (string)
  • Map ID for which to set the options
• mapOptions ({ renderMaps?: boolean | undefined; renderLines?: boolean | undefined; renderPoints?: boolean | undefined; renderGcps?: boolean | undefined; renderGcpsColor?: string | undefined; renderGcpsSize?: number | undefined; renderGcpsBorderColor?: string | undefined; ... 54 more ...; distortionMeasure?: DistortionMeasure | ...)
  • Map-specific options to set
• layerOptions? ( | Partial<WebGL2RenderOptions> | Partial<SpecificWarpedMapLayerOptions> | undefined)
  • Layer options to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

Examples

warpedMapLayer.setMapOptions(myMapId, { transformationType: 'thinPlateSpline' })

BaseWarpedMapLayer#setMapResourceMask(mapId, resourceMask, animationOptions)

Set the resource mask of a map

This only sets the map-specific resourceMask option of the map (or more specifically of the warped map used for rendering), overwriting the original resource mask inferred from the Georeference Annotation.

The original resource mask can be reset by resetting the map-specific resource mask option, and stays accessible in the warped map's map property.

Parameters

• mapId (string)
  • Map ID for which to set the options
• resourceMask (Array<Point>)
  • Resource mask to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

BaseWarpedMapLayer#setMapTransformationType(mapId, transformationType, animationOptions)

Set the transformation type of a map

This only sets the map-specific transformationType option of the map (or more specifically of the warped map used for rendering), overwriting the original transformation type inferred from the Georeference Annotation.

The original transformation type can be reset by resetting the map-specific transformation type option, and stays accessible in the warped map's map property.

Parameters

• mapId (string)
  • Map ID for which to set the options
• transformationType ( | 'straight' | 'helmert' | 'polynomial' | 'polynomial1' | 'polynomial2' | 'polynomial3' | 'thinPlateSpline' | 'projective' | 'linear')
  • Transformation type to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

BaseWarpedMapLayer#setMapsOptions(mapIds, mapOptions, layerOptions, animationOptions)

Set the map-specific options of maps (and the layer options)

In general setting a map-specific option also sets the corresponding option of the map, since these are the result of merging the default, georeferenced map, layer and map-specific options of that map.

A special case is setting a map-specific option to undefined: then the corresponding option is derived from the default, georeferenced map or layer option. This is equivalent to using the reset function for map-specific option.

Parameters

• mapIds (Array<string>)
  • Map IDs for which to set the options
• mapOptions ({ renderMaps?: boolean | undefined; renderLines?: boolean | undefined; renderPoints?: boolean | undefined; renderGcps?: boolean | undefined; renderGcpsColor?: string | undefined; renderGcpsSize?: number | undefined; renderGcpsBorderColor?: string | undefined; ... 54 more ...; distortionMeasure?: DistortionMeasure | ...)
  • Map-specific options to set
• layerOptions? ( | Partial<WebGL2RenderOptions> | Partial<SpecificWarpedMapLayerOptions> | undefined)
  • Layer options to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

Examples

warpedMapLayer.setMapsOptions([myMapId], { transformationType: 'thinPlateSpline' })

BaseWarpedMapLayer#setMapsOptionsByMapId(mapOptionsByMapId, layerOptions, animationOptions)

Set the map-specific options of maps by map ID (and the layer options)

In general setting a map-specific option also sets the corresponding option of the map, since these are the result of merging the default, georeferenced map, layer and map-specific options of that map.

A special case is setting a map-specific option to undefined: then the corresponding option is derived from the default, georeferenced map or layer option. This is equivalent to using the reset function for map-specific option.

Parameters

• mapOptionsByMapId (Map<string, Partial<WebGL2WarpedMapOptions>>)
  • Map-specific options to set by map ID
• layerOptions? ( | Partial<WebGL2RenderOptions> | Partial<SpecificWarpedMapLayerOptions> | undefined)
  • Layer options to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

BaseWarpedMapLayer#setOpacity(opacity)

Set the layer opacity

Parameters

• opacity (number)
  • Layer opacity to set

Returns

void.

BaseWarpedMapLayer.assertCanvas(canvas)

Parameters

• canvas? (HTMLCanvasElement | undefined)

Returns

void.

BaseWarpedMapLayer.assertRenderer(renderer)

Parameters

• renderer? (WebGL2Renderer | undefined)

Returns

void.